Synthesis and Optical Properties of Copolymers
117=[397]
levels of the copolymers might provide a close match to the function of
hole-injecting PEDOT layer, especially when they were used as hole-
transporting materials in the PLEDs. It was also found that the incor-
poration of the 1,3,4-oxadiazole group in the polymer side chain
reduced the electronic band gap energy level of the copolymer, which
might be explained by more conjugation formed in the molecular chain
by introducing 1,3,4-oxadiazole pendant groups in the side chain.
CONCLUSIONS
Conjugated copolymer, P(3,6-EHCZ-alt-MPAOXD), consisting of a
triarylamine and a carbazole groups (hole transporting ability with
blue emission) in the main chain as well as the electron transporting
1
,3,4-oxadiazole pendant moiety was synthesized through palladium-
catalyzed polycondensation. For comparison, P(3,6-EHCZ-alt-AL) with
a triarylamine and a carbazole groups in the main chain was also
synthesized and characterized. The optical and electrochemical results
revealed that the incorporation of the 1,3,4-oxadiazole group in the
polymer side chain reduced the electronic band gap energy level of
the copolymer. It was also found that the copolymers could be used
as hole-transporting materials in the PLEDs, due to closely matched
HOMO energy levels between the copolymers and hole-injecting
PEDOT layer.
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